Ninhydrin is one of the best and easiest methods for developing latent prints on paper, such as bad checks, robbery notes, drug pay-and-owe sheets, and threatening letters. Many latent print examiners use Ninhydrin exclusively on paper documents because it is effective and/or they do not have the proper setup and/or Forensic Light Source for using DFO.

Mixing Ninhydrin crystals is very economical, as little as 3.8 grams of crystals produce 2 liters of solution, and the shelf life is indefinite. The solution can be swabbed, sprayed, or dipped in solution for maximum saturation. Photograph the developed prints soon after they become visible. Avoid handling the treated document, as new latent prints may develop on the chemically-sensitive paper. Since the solvents are hazardous, this solution must be mixed and used in a fume hood. View our Technical Note for more information.